Muscles of the arm and cubital fossa Flashcards
Describe the origin, insertion and nerve innervation of the coracobrachialis;
'O' = Coracoid process 'I' = Medial side of humerus opposite deltoid tuberosity
nerve = Musculocutaneous
Describe the origin, insertion and nerve innervation of the brachialis;
‘O’ = Anterior surface of the distal humerus (including intermuscular septa)
‘I’ = Tuberosity of ulna
Nerve = musculocutaneous
What nerves innervate the posterior compartment?
Radial nerve
Describe the origin, insertion and nerve innervation of the biceps brachii;
Origin;
Long head; Supraglenoid tubercle
Short head; Coracoid process
Insertion; radial tuberosity and biceptial aponeurosis
Nerve = Musculocutaneous
Describe the movement of the different deltoid fibres;
Anterior fibres:
- Flex shoulder
- Internally rotates arm
- Abduct/adducts the arm (depends on position)
Posterior fibres:
- Extend shoulder
- Externally rotates arm
- Abduct/adducts arm (depends on position)
Middle fibres
- Abducts arm
Describe the deltoid fibres;
Anterior fibres (Unipennate) Posterior fibres (unipennate) Middle fibres (Multipennate)
Unipennate = Strong Multipennate = Very strong
Describe the borders of the cubtal fossa;
Superior border is formed by the ‘line’ between the lateral and medial epicondyles
Medial border; Pronator teres
Lateral boundary; Brachioradialis.
Describe teres major origin, insertion and nerve innervation;
'O' = Inferior angle and lateral border of scapula 'I' = Medial lip of intertubercular groove
Nerve = Lower subscapular
What muscles are found in the posterior compartment?
Triceps brachii
Describe the origin and insertion of the deltoid;
'O' = Anatomical horseshoe 'I' = Deltoid tuberosity
Describe the compartments of the brachium;
Posterior and anterior compartments at the mid level of the humerus.
At the distal end of the humerus there is also Ext./Sup. compartment on the lateral side and Flex./Pro. compartment of the medial side.
What nerve innervates the anterior compartment?
Musculocutaneous nerve
What muscles are found in the anterior compartment of the arm?
Biceps brachii
Coracobrachialis
Brachialis
Describe the origin, insertion and nerve innervation of the triceps brachii;
‘O’
- Long head = Infraglenoid tubercle
- Medial head = medial aspect of humerus
- Lateral head = Lateral aspect of humerus
‘I’ = Olecranon (Ulna)
Nerve = Radial nerve.